Perhaps I should explain my reasonings as to why I am certain that Misty is most likely Returning to the main cast. You see, I at first thought that she might have meant that she was returning thanks to that blog, but when Cybercubed mentioned that it could have been VA stuff/10th anniversary stuff, I was firmly believing that she will return to the main cast, and I also doubted the part of her doing VA specials since she somewhat confirmed the VA stuff (she was mentioning her first trivia segment, so it was pretty much confirmed that she was doing specials) and yet it also stated right afterwards that she hinted at a further appearance sometime in the future, and since, Logically speaking, no human would hint at something after they confirmed said thing in the same source, that somewhat disproved the whole VA special exclusive stuff that he mentioned.
I also noticed during my research on bulbanews that the march the 3rd blog was the first Mayumi Iizuka blog/interview that delt with a possible future appearance/return of Misty to even be posted on Bulbanews (much less the possibility of it being the first blog to even hint at Misty returning at all)
(although I am unsure of whether the mirage togepi arc or the Hoenn League Tourney cameo had been mentioned in any past blogs of Mayumi Iizuka, I do know that her three episode arc near the end of advanced battle and even her role in the 10th anniversary anime special "Mastermind of Mirage Pokemon" were definitely not even touched upon by her VA, since if they were, they would have posted it on bulbanews.).
Prior to March the 3rd, the only way we could get info involving Misty's return were Pokeani, commercials for the next episode, and other stuff. And, to my knowledge at least, there hasn't been a blog from her VA that even gives a hint at Misty's return/appearance.
So these points, as well as my sending out that Letter that basically told them that either they bring Misty back onto the show or the entire Misty fanbase will Boycott their franchise way back in November of last year, is the reason why I am under the firm belief that Her VA did indeed mean that Misty is returning to the Main Cast in her hint in that blog. So, to me at least, it seems very likely that Misty is indeed returning to the main cast. However, we will have to wait until possibly the 11th season to find out if it is indeed the case or not. And even if she doesn't end up returning to the main cast, we always have Plan B (the Petitions and Operation Global Boycott.).
@Peachesncream, I signed Your Petition, it's the one that mentions Misty being the only one who is not of the female anime stereotype.
